Minimally invasive polyaxial locking plate osteosynthesis for 3-4 part proximal humeral fractures: our institutional experience.

INTRODUCTION: The objectives of this study were to describe the surgical technique of fixation of 3-4 part proximal humeral fractures with polyaxial locking plates utilising a minimally invasive approach and to evaluate the accuracy of reduction and stability of fixation.

PATIENTS AND METHODS: We retrospectively reviewed 90 patients. Fractures were classified according to the Neer classification system. Different radiological parameters were measured to assess the quality of reduction and the stability of fixation. Complications and clinical outcomes were evaluated after one year of minimum follow up.

RESULTS: There were 76 women and 14 men, with a mean age of 67.4years ±13 (range, 29-85). There were 60 3-part and 30 4-part fractures. Frozen cancellous allograft was used in 30 cases (33.3%). All fractures progressed to union and at one year follow up, the mean Constant score was 79.6±12(range, 62-100). Mean forward flexion, abduction, external rotation and internal rotation were 155°, 148°, 39° and vertebra Dorsal 8, respectively. Complications were noted in seven patients while the postoperative "head-diaphysis angle", "greater tuberosity height" and "medial metaphysis reconstruction" were close to the anatomical parameters; no significant differences were noted at one year radiological follow up.

CONCLUSION: Reliable and stable fixation can be expected with the use of polyaxial locking plate through a minimally invasive approach for the treatment of 3-4 part proximal humeral fractures. Satisfactory functional results for this procedure can be obtained.